In the handling of digital information the matter of storing digital information often becomes critical. For many purposes, floppy disks are an acceptable form of storage, and when more capacity than that available on a floppy disk is required, additional floppy disks may be inserted into the unit as others are removed. In addition, more than one floppy disk drive may be employed. When a greater amount of high speed random access disk storage is required, rigid disks are the next step up toward increased capacity. However, up to the present time, the 14 inch disks which have been available have been relatively costly. In addition, 14 inch fixed rigid disk drives tend to have excessive power consumption and inadequate access time, in addition to the undesirably large physical size and weight of such units.
Another problem encountered in the rigid disk storage units which have been used and proposed up to the present time, has been the problem of maintaining the surface between the disk and the recording head entirely free from dust and dirt, as very clean conditions are absolutely necessary for error-free high density recording and pick-up of digital information. In working toward this goal, various air handling arrangements have been proposed up to the present time, but these have generally been relatively elaborate and wasteful of space. Various units have employed separate blowers, special ducts in the casting for the units, etc. One other design deficiency has been the inclusion in many cases of the electronics in the same area with the disks, or soldered onto printed circuit boards, defining a part of the enclosure in which the disks are located. Accordingly, when a minor fault requires access to the printed circuit boards for replacement or the like, additional dirt and dust is introduced into the area where the disks and heads are located, thus significantly reducing the advantages which might otherwise be obtained through the use of the blower systems.
Accordingly, a principal object of the present invention is to provide a reliable high density rigid disk digital storage system. A subordinate object of the invention is to maintain the interface between the disks and the read and write heads free of dust and dirt, while concurrently reducing the overall size and capacity of the digital storage system.